Recently, electrooptical devices have been commonly used in electronic apparatuses such as cellular phones and portable personal computers. Transflective liquid crystal devices, which can perform both reflective display and transmissive display, are known as one of such electrooptical devices.
When a transflective liquid crystal device performs reflective display, external light such as natural light and room light enters the liquid crystal device and is reflected by a reflective layer provided in the liquid crystal device. Thus, an image is displayed when the reflected light is emitted to the outside. The reflective layer must also have a function to transmit light so that the liquid crystal device can also perform transmissive display. Accordingly, when external light is reflected by the reflective layer as described above, only a part of the external light is reflected.
The above-described reflective structure including the reflective layer reflecting external light is similar to that of a liquid crystal device which does not have a function to perform transmissive display, that is, a liquid crystal device which reflects all of the external light with a reflective layer, that is, a reflective liquid crystal device.
Meanwhile, in a liquid crystal device which can perform reflective display, irrespective of whether it is a transflective liquid crystal device or a reflective liquid crystal device, there is a problem in that when the surface of the reflective layer is mirror-finished, a displayed image cannot be seen clearly by a viewer due to the reflection of objects and room lights on the image.
In order to solve the above-described problem, a technique has been proposed in which an underlayer having many small irregularities in the surface thereof is disposed under a reflective layer. Thus, many small convexities are formed in the surface of the reflective layer. Accordingly the surface roughness is increased, so that the reflected light is moderately scattered.
Japanese Laid-Open Patent Application Publication No. 2002-258270.
In liquid crystal devices, many display dots, as a single display dot serves the minimum display unit, are arranged along a plane in, for example, a matrix pattern. A desired image is displayed by selectively illuminating the display dots. In such a case, a light-shielding layer, that is, a layer which prevents light from passing therethrough, is disposed so as to cover the regions between the display dots. This light-shielding layer, called a black mask or a black matrix, is formed so that a high-contrast image can be displayed.
When a light-shielding layer is provided to cover the regions between the display dots, the thickness increases at the regions where the light-shielding layer is provided. Accordingly, there are problems in that a cell gap becomes nonuniform and a rubbing process of an alignment film cannot be performed under satisfactory conditions. Although a substrate surface becomes relatively planar when an alignment layer and an overcoat layer are generally formed on the light-shielding layer, the above-described problems of nonuniform cell gap, etc., cannot be solved.
In view of the above-described situations, an object of the present invention is to reduce the surface roughness over regions where the display dots are arranged and regions between the display dots. In addition, it is also an object of the present invention to ensure the planarity over the regions where the light-shielding layer is formed and regions surrounded by the light-shielding layer, for example, regions where color layers are formed.